EPA finalizes Cross-State Air Pollution Rule (Transport Rule)

7 July 2011

Transport Rule states. Source: EPA. Click to enlarge.

The US Environmental Protection Agency (EPA) has finalized the new Cross-State Air Pollution Rule (CSAPR) (also called the Transport Rule). The Cross-State Air Pollution Rule replaces and strengthens the requirements of the 2005 Clean Air Interstate Rule (CAIR), which the US Court of Appeals for the DC Circuit ordered EPA to revise in 2008. (The court allowed CAIR to remain in place temporarily while EPA worked to finalize the replacement rule.)

Carried long distances across the country by wind and weather, power plant emissions of sulfur dioxide (SO2) and nitrogen oxide (NOx) continually travel across state lines. The rule will improve air quality by cutting SO2 and NOx emissions that contribute to pollution problems in other states. By 2014, the rule and other state and EPA actions will reduce SO2 emissions by 73% from 2005 levels. NOx emissions will drop by 54%.

Once EPA determined these obligations, including the
amount of necessary pollution reductions, it set state budgets accordingly, with variability limits to assure that each state will meet its pollution control obligations.

The rule allows air quality-assured allowance trading
among power plants, utilizing an allowance market
infrastructure based on existing, successful allowance
trading programs.

Annual SO2 Power Plant Emissions
1990-2014. Click to enlarge.

Annual NOx Power Plant Emissions
1990-2014. Click to enlarge.

Ozone Season NOx Power Plant Emissions
1997-2014. Click to enlarge.

Under the rule, 27 states in the eastern half of the country will work with power plants to cut air pollution, which leverages widely available, proven and cost-effective control technologies. EPA will work with states to help develop the most appropriate path forward to deliver significant reductions in harmful emissions while minimizing costs for utilities and consumers.

The rule will protect over 240 million Americans living in the eastern half of the country, resulting in up to $280 billion in annual benefits, EPA says. The benefits outweigh the $800 million projected to be spent annually on this rule in 2014 and the roughly $1.6 billion per year in capital investments already underway as a result of CAIR.

In a supplemental rulemaking based on further review and analysis of air quality information, EPA is also proposing to require sources in Iowa, Kansas, Michigan, Missouri, Oklahoma, and Wisconsin to reduce NOx emissions during the summertime ozone season. The proposal would increase the total number of states covered by the rule from 27 to 28. Five of these six states are covered for other pollutants under the rule. The proposal is open for public review and comment for 45 days after publication in the Federal Register.